DESCRIPTION: This proposal requests support for a four-year follow-up study of the adolescent consequences of very low birthweight (VLBW less than 1.5 Kg). A cohort of 249 LBW born in 1977-1979 was studied longitudinally at five previous times: birth, expected term date, 8 months, 2 years, and 8 years of age. Data were obtained on sociodemographic and perinatal variables at birth and on growth, disease variables and neurodevelopmental status at all subsequent time points. At 8 years of age, outcomes were compared to a regional comparison group of 363 normal birthweight (NBW) children. The proposed study will extend the longitudinal data set to 18 years of age. At this time it will also include a sibling control group. Follow up data will be gathered on growth attainment, health, psychosocial development, individual functioning and peer and family relationships. The investigators will test the following hypotheses regarding VLBW at 18 years of age compared to NBW controls and same sex and age appropriate siblings: 1) VLBW will demonstrate catch up in growth but will have lower ponderal indices and a later history of puberty onset; 2) VLBW will demonstrate significant differences in health measures -- more respiratory symptoms, lower blood pressure and poorer motor functioning; and 3) VLBW will demonstrate significantly poorer academic and psychosocial functioning, poorer perceived competence and more behavioral symptoms (which will be associated with higher levels of drug abuse and violent behavior), and poorer peer and family relationships. The investigators also hypothesize that the outcomes described in Hypothesis 3 will be worse in adolescents with subnormal cognition and from socially disadvantaged families. The data analytic plan is to examine the direct effects of VLBW on 18 year outcomes as well as the mediating and moderating influences of intervening variables which may affect this relationship. Data will be gathered from adolescents and mothers via structured interviews and questionnaires, a standardized IQ test, and growth and blood pressure measurements. Data will be merged with previously documented measures. Three types of analyses will be performed: 1) con-current comparisons of VLBW and controls; 2) longitudinal outcomes; and 3) internal comparisons between subsets of VLBW children. The plan to examine functional outcomes of VLBW adolescents as individuals and among their peers and family will provide a societal and life span perspective of the consequences of VLBW. The results have implications concerning the current aggressive neonatal care of extremely immature infants.